This proposal requests continued funding to support the Pediatric Oncology program of the State University of New York (SUNY). Health Science Center at Syracuse, in its participation within the Pediatric Oncology Group (POG). The institutional program in Pediatric Oncology Is an interdisciplinary one, involving the Departments of Radiation Oncology, Pediatric Surgery, Pathology, Immunology, Neurosurgery, and Neurology, as well as the Division of Pediatric Hematology-Oncology. Funding of the Syracuse program will permit the continuation of its excellent record of evaluable patient entry onto POG studies. It will also allow the continuation of its investigators' significant scientific and administrative contributions to POG. Syracuse faculty have played key roles in developing and coordinating protocols #8849 (hydroxyurea-araC in refractory leukemia), #8823/24 (alpha interferon In CML), and #8973 (etoposide plus continuous infusion carboplatin in refractory leukemia). New protocols to be initiated from this institution will include a combination interferon-chemotherapy protocol for ACML, and a laboratory study utilizing an assay for TdT RNA in remission marrow specimens from patients with ALL, in which preliminary findings, relating the presence of elevated values to subsequent reslapse, will be tested prospectively. The active participation of Syracuse investigators on many POG committees, particularly that of the Data Manager, will be made possible by continuation of funded support.